Re: PNP patch into kernel when?

Alan Cox (
Fri, 6 Dec 1996 23:19:20 +0000 (GMT)

> Writing an _intelligent_ config manager is a complete nightmare!

It seems to reduce to the knapsack problem, which is unfortunate cos
thats NP complete.

> * Drvier for Card A has allocated IRQ 5 (via PnP or some other
> mechanism)
> * Card B has no method of autoconfiguring, and the driver wants to
> probe an IRQ. Unfortunately, it is using IRQ 5, which does not
> get probed, because it is already allocated. So, the IRQ
> reallocation code never gets used anyway with cards that cannot
> read their IRQ from config registers, and therefore probably
> support dynamic reconfiguration anyway!

I think you start with fixed devices, then devices with limited support
for changes then stuff the PnP kit in the gaps

> As a side point, is it worth implementing a much more complex
> configuration manager as a user-side daemon, and have a very simple
> configuration manager in the kernel itself?

That sounds a good plan.